Conventionally known is a rotary connector device for electrically connecting a rotatable side and a fixed side, such as a steering side and a vehicle body side of a vehicle, to each other. In general, a steering of a vehicle is provided with a device, such as an airbag, that is required to ensure a reliable operation in an emergency situation. Accordingly, not a sliding electrode or the like having low reliability but a rotary connector configured to connect a steering side and a vehicle body side to each other by a flexible flat cable or the like wrapped with looseness is adopted.
Here, the flexible flat cable is a plurality of thin conductor parts coated by resin or the like. In general, the flexible flat cable and an external electrical component are connected via a connecting tool shown in Patent Documents 1 to 3.
As shown in Patent Document 1 and Patent Document 2, the connecting tool includes a plurality of bus bars (pin terminals) made of metal and an insulating part (a supporting member) made of resin. In Patent Document 1 and 2, insertion holes are formed on a side surface of the insulating part, and the bus bars can be fixed by inserting (press-fitting) the bus bars into the insertion holes.
In Patent Document 3, firstly, bus bars (pin terminals) are caulked and connected to covered electric wires. Then, the bus bars are fixed by inserting the caulked bus bar into an insulating part (a supporting member) made of resin.